Method and means for carbonating liquids in situ

ABSTRACT

This invention provides a novel method and means for carbonating liquids in the container from which the liquids are served to the consumer with a minimum of carbonating gas and for maintaining and enhancing carbonation of the remaining liquid without expensive regulatory apparatus after withdrawal of a portion of the carbonated liquid. Inherent in the means and method to induce and regulate carbonation, the invention provides both means and method for regulating or substantially limiting the maximum volume of liquid introduced into the carbonation chamber as well as a means and method to purge air from the carbonation chamber. According to the invention, a fixed volume vessel and a dynamic capacity carbonating chamber, a pump and relief valves enable consistent carbonation and regulation of the carbonating pressure prior to and following dispensing of carbonated liquids while utilizing a finite, minimum quantity of carbonating gas. The dynamic capacity carbonating chamber is defined within a fixed volume vessel by a resilient, flexible relatively non-permeable air bag separating a liquid CO 2  gas phase from pressurized air. A manually operated pump and preset relief valves enable the maintenance of predetermined fixed pressures within the air chamber and carbonating chamber of the vessel without introducing atmospheric air into the carbonating chamber.

BACKGROUND OF THE INVENTION

There are two basic types of carbonation, natural and artificial. Onepertinent means of natural carbonation depends upon the action offermenting yeasts upon residual sugar in solution. Yeast, in thepresence of sugar, produces alcohol and carbon dioxide as end productsof the fermentation process. In order to obtain natural yeast actioncarbonation, an appropriate amount of fermentable sugar is placed withinthe fixed volume of a container along with the yeast-beverage solution.After secure capping, the pressure increases in direct proportion to therate of fermentation which is further dependent upon factors such as theamount of available fermentable sugar, relative proportion of yeast tosugar, temperature, and time.

Natural carbonation has the advantage of being done in situ or in thesame container from which the contents are served to the consumer andhas the advantage of eliminating the transfer of carbonated liquid andthe consequent loss of carbonation during transfer. But the naturalcarbonation process described inherently has variances in carbonationlevel because of the several variables noted above. Another disadvantageis the length of time it takes for natural carbonation. As much as twoweeks must be allowed for the beverage to adequately carbonate andsettle yeast sediment. Additionally, the said natural carbonationprocess invariably includes air in the headspace and correspondingdetrimental effects of oxygen, flavor loss and improper carbonationpressure; and any coincidental production of alcohol may be undesirablein soft drink formulations. Beverages such as soda water, club soda,quinine water, and carbonated mineral waters cannot be made by naturalcarbonation because there is no sugar in their recipes.

Artificial carbonation is achieved by introducing carbon dioxide gasinto liquid within a fixed volume container under pressure. The gasdiffuses rapidly into the liquid under adequate pressure and cooltemperatures. But the withdrawal of carbonated liquid from a fixedvolume container decreases the carbon dioxide pressure within thecarbonated liquid remaining in the container in proportion to the volumeof liquid withdrawn.

Some prior art devices compensate for the loss of carbon dioxidepressure when carbonated liquid is withdrawn from the container byintroducing additional carbon dioxide under pressure into the fixedvolume container in direct proportion to the loss of carbon dioxidepressure occasioned by the withdrawal of carbonated liquid from thecontainer. Other prior art devices attempt restoration of carbon dioxidewithout regulation.

Some prior art carbonating devices include a diaphragm or air bag intheir structure but to applicant's knowledge no prior art device uses adiaphragm or air bag as a principle in carbonation, or in combinationwith an air pump and relief valves to induce or to maintain a uniformpressure after carbonated liquid is withdrawn. The following disclosuresshow the state of the art known to applicant regarding the use ofdiaphragms or air bags in carbonation devices: U.S. Pat. No. 978,103issued Dec. 6, 1910 to Charles L. Bastion, U.S. Pat. No. 935,698 issuedOct. 5, 1909 to Lewis Silberschmidt, British Pat. No. 11,914 of 1912 toKoenig and Stahl, Swedish Pat. No. 27,648 issued Aug. 24, 1907 to O. E.Ohlsson, and Danish Pat. No. 52,417 issued Dec. 7, 1936 to Hans Andvigand Johannes Freng.

SUMMARY OF THE INVENTION

According to the present invention, a carbonating apparatus providingmaximum carbonation with a minimum of carbon dioxide gas is particularlysuited for home use. The apparatus includes means for providing uniformpredetermined pressure on the liquid during carbonation afterequilibrium has been established and after withdrawal of a portion ofthe carbonated liquid.

The carbonator of the present invention includes a fixed volumecontainer having rigid walls and containing a flexible, impervious,variable volume air bag. The space between the air bag and the innerwall of the vessel defines a carbonating chamber to contain liquid forcarbonation. The container also includes a closure body which serves asa control block and houses a pump by which the air bag is filled withatmospheric air. The control block also houses a fixed supply of carbondioxide gas and means for introducing the gas into the carbonatingchamber exteriorly of the air bag. The control block also includes a tapfor withdrawing liquid from the carbonating chamber.

Means are provided for readily removing the control block for cleaningand to gain access to the air bag and other operative parts within thevessel for maintenance. Liquid to be carbonated may be introduced intothe carbonating chamber while the control block is removed, but forhygenic and regulatory control it is preferred to add liquid to thecarbonating chamber by utilizing the carbonating apparatus, specificallythe controlled release of air from the expanded air bag to inducesiphoning of liquid from a source outside the fully assembledcarbonating container into the carbonating chamber. Similarly, acleaning agent such as sodium metabisulfate may be drawn into thecarbonating chamber prior to use to rinse the chamber and passagewayswithout removing the control block.

It is an object of this invention to provide a carbonator including acarbonating chamber into which liquid to be carbonated may beintroduced; means for introducing a fixed quantity of carbon dioxide gasinto the carbonating chamber; means to vent excessive carbon dioxide;means for introducing and regulating the volume of liquid to becarbonated; and means to purge air from the carbonation chamber.

In the illustrated embodiment, a sealed air bag within the carbonatingchamber communicates with means to introduce atmospheric air to the bagand with means to vent air from the bag to the atmosphere above apredetermined pressure. The air bag may be expanded by pumpingatmospheric air into it to expand the volume of space occupied by thebag within the container and thereby apply pressure to the contents ofthe carbonating chamber. The air bag is expandable to occupy the spaceleft within the vessel when some of the liquid is withdrawn through atap communicating with the carbonating chamber. An air relief valvevents air from the bag to the atmosphere in excess of a predeterminedpressure.

It is another object of this invention to provide a novel method forcarbonating a liquid within a household for home use, which methodcomprises the steps of providing a fixed volume container, providing avariable volume air bag within the container and a carbonating chamberwithin the container and exteriorly of the air bag, introducing liquidinto the carbonating chamber, introducing carbon dioxide gas into theliquid, introducing atmospheric air under pressure into the air bag toexpand the bag within the container and apply pressure on the liquid tofacilitate carbonation, withdrawing a portion of the carbonated liquid,and introducing an additional volume of air into the bag to expand thebag and compensate for the volume of liquid removed from the carbonatingchamber, thereby restoring the desired carbonating pressure to theliquid. Adjustable relief valves are provided in communication with thecarbonating chamber and in communication with the interior of the bagand are pre-set at desired pressure levels to draw off excess carbondioxide and excess air, respectively.

The container is preferably of a size to hold one to two gallons ofliquid and to conveniently fit within a household refrigerator, althoughthe container may be of any desired size and may be used commercially.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the carbonating container illustratingelevation of the spout to withdraw carbonated liquid from thecarbonating chamber;

FIG. 2 is a front elevation of the carbonating container with partsbroken away to show the air bag and carbonating chamber within thecontainer;

FIG. 3 is a horizontal sectional view through the control block of thecontainer taken substantially along the line A--A in FIG. 2; and

FIG. 4 is a vertical sectional view with parts broken away takensubstantially along the line B--B in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring more specifically to the drawings, the carbonating containeris broadly indicated by the numeral 1. The container 1 is defined by apressure containing rigid wall 2 of generally cylindrical configuration.Access to the interior of the container 1 may be gained by removing aclosure plate which also serves as a control block 3 from the front ofthe container. The control block 3 includes an inner portion 4 and theportions 3 and 4 clamp about the edges of an opening in the front wallof container 1. Set screws 5 connect the outer and inner portions 3 and4 of the closure plate and compress a rubber seal 6 to form a leakproof, pressure tight seal.

A tap ball valve 7 having a liquid passageway 8 and a tap spout 9 isjournaled in sockets 12 of the plates 3 and 4. Set screws 5 fasten thevalve 7 and inner portion 4 of the control block 3 tightly together. Atubular passageway 14 is formed within inner portion 4 of the controlblock 3 between the socket 12 and the inner wall of portion 4 of controlblock 3. The inner end of tubular passageway 14 communicates with a tappick-up 17 within carbonating chamber 15 of container 1, and the outerend of passageway 14 communicates with passageway 8 in valve 7. O-rings10 and 11 extend about valve 7 at its juncture with passageway 14 and atthe innerface of outer and inner portions 3 and 4 of the control block.

The carbonating chamber 15 occupies substantially all of the spacewithin container 1 except that space occupied by an air bag 16. Thespace occupied by air bag 16 is variable depending upon the amount ofair within it. Air from the atmosphere is introduced into bag 16 bymanually actuating a pump bulb 18 to force air from pump 19 into the bag16 through passageway 23 around check valve 28. Air is drawn into thepump 19 from the atmosphere through passageway 20 in the inner portion 4of control block 3. The bag 16 has a bead 26 and is attached to theinner portion 4 of control block 3 by a plate 24 and screws 25. AnO-ring 27 preferably extends about the passageway 23 to prevent leakageof air during its passage from pump 19 through check valve 28 into theinterior of bag 16.

The interior of bag 16 is vented to the atmosphere through a passageway31 extending through inner plate 4 between the interior of bag 16 and arelief valve 30 within inner plate 4 and vented to the atmosphere. Therelief valve 30 is spring loaded and is threadably adjustable to relievepressure at a predetermined setting thereby enabling the establishmentof a predetermined carbonating pressure in the carbonation chamber. Thisis desirable because beverages differ in "volume" or level ofcarbonation. The quickest and highest carbonation is not necessarily thebest nor the desired level of carbonation for all beverages. Forexample, beer is carbonated substantially lower than soda water.Carbonation is facilitated by chilling the liquid, and the temperatureat which the liquid is carbonated has an effect on the optimumcarbonating pressure. Assuming a constant carbonating temperature of 40degrees, relief valve 30 may be manually adjusted to vent the air bag 16at a high or low carbonating pressure to achieve the desired carbonationof the beverage with a minimum predetermined amount of carbon dioxide. Aspring loaded pressure relief valve 48 is threadably adjustable asindicated at 39 in FIG. 2 to establish the pressure at which air orcarbon dioxide gas may be allowed to escape from carbonating chamber 15to the atmosphere. The carbon dioxide relief valve 48 is preset at ahigher pressure than the air relief valve 30 so that valve 48functionally prohibits the release of carbon dioxide gas during normaloperation, conserving carbon dioxide. Valve 48 functions both as asafety valve and to purge the carbonating chamber externally of the bag16. A passageway 49 extends from relief valve 48 through inner plate 4and is joined with a carbon dioxide relief pick-up tube 38 terminatingadjacent the top of container 1.

The liquid to be carbonated may be introduced into the carbonatingchamber 15 by removing control block 3 and pouring the liquid into thechamber 15 through the hole in the wall of container 1 created byremoval of block 3, but preferably the liquid is inserted in thecarbonating chamber 15 without removing block 3 by (1) adjusting therelief valve 48 to vent the chamber to the atmosphere at pressures lowerthan that set for relief valve 30, (2) pumping air into the resilientair bag 16 which expands until it reaches limits defined by thecontainer walls 2 and expels air from the carbonating chamber 15 throughrelief valve 48, (3) opening the valve 7 to establish communicationbetween carbonating chamber 15 and spout 9, (4) attaching one end of adetachable tube T to the spout 9 and submerging the other end of tube Tin the liquid to be carbonated, and (5) venting the air contained withinthe air bag 16 to the atmosphere through relief valve 30. It isimportant that relief valve 48 be reset to vent pressure in excess ofthe desired amount of pressure to be used during and after carbonation.

When the expanded air bag 16 is vented, it contracts with a forcedirectly proportional to its elastic qualities and degree of expansion.The reduction of the volume of air within the bag relative to totalvolume of the container causes a depressurization in carbonating chamber15 and the drawing of liquid through tube T into chamber 15 until thepressures within chamber 15 and bag 16 reach equilibrium.

By controlling the optimum input of liquid into the carbonating chamberfor desired carbonation, one is able to fix at equilibrium both thevolume of air contained within the bag and the volume of contents of thecarbonating chamber 15. The preferred siphoning of liquid into thecarbonating chamber is also advantageously hygenic and promotes safetyby controlling the potential pressurization of chamber 15.

Any air remaining within the carbonation chamber 15 after it is filledwith liquid to the point of equilibrium should be purged from thecontainer through steps which comprise closing the valve 7 to tap 9,removing the tube T and operating the pump 19 to expand the bag 16 andforce any air contained in the upper portion of carbonating chamber 15through the relief valve 48 which had been and is set to vent atpressures lower than relief valve 30.

After the chamber 15 has been purged of air and liquid has been put inthe carbonating chamber 15 relief valve 48 must be reset to vent atpressures higher than relief valve 30. Carbon dioxide gas may then beadded to the carbonation chamber for diffusion into the liquid byinserting a carbon dioxide cartridge 40 into a threaded injector cap 41and fitting a rubber neck ring 42 over the cartridge neck 43. Theinjector cap 41 with the cartridge 40 inside of it is threaded onto theinner portion 4 of control block 3 until the inner end of cartridge 40is punctured by point 44 communicating with passageway 45 in portion 4.The rubber neck ring 42 seals the neck 43 of cartridge 40 to preventescape of carbon dioxide gas except through passageway 45 intocarbonating chamber 15. Passageway 45 communicates with check valve 47in carbonating chamber 15 which blocks carbon dioxide gas and liquidfrom passing outwardly through passageway 45.

Carbonation of liquid is affected by temperature and pressure. The lowerthe temperature and the higher the pressure the quicker and morecomplete is the carbonation. A lot of carbonation as for soda water, ora relatively little carbonation, as for beer, can be achieved andmaintained with this invention through use of the air bag 16 to exert aconstant predetermined pressure at a given temperature on the liquidwhile it is being carbonated after equilibrium is established.

In use, a controlled quantity of liquid introduced is siphoned into thecontainer, which coincidentally promotes hygiene, safe working volumes,and enables the liquid to be drawn through an in-line millipore filter(not shown) to remove any incoming yeast or bacteria, if desired. Carbondioxide is subsequently introduced into the carbonating chamber 15 fromcartridge 40 through passageway 45, and then the air bag 16 is expandedwithin chamber 15 by actuation of pump 19 until the pressure within bag16 reaches the predetermined value for which the relief valve 30 hasbeen set. This set pressure is that which has been found effective toproduce a desired degree of carbonation for a particular beverage at thetemperature at which it is being carbonated.

As carbonation begins, the pressure within the carbonating chamber 15will decrease as the carbon dioxide diffuses into the liquid until thepressure within chamber 15 corresponds with pressure transmitted by theair bag 16. The pressure within chamber 15 continues to decrease ascarbonation proceeds until an equilibrium between gas dissolved in theliquid and the gas above is established. Until this equilibrium isestablished at the desired carbonating pressure it may be necessary tooperate the pump 19 to add pressure to the air bag 16 and consequentlyto the carbonating chamber 15 as the bag 16 expands within the chamber15.

Carbonated liquid may be drawn from chamber 15 by elevating spout 9 tothe solid line position of FIG. 4 to open valve 7 by aligning the liquidpassageway 8 with the passageway 14 and tube 17 to draw liquid fromchamber 15. The withdrawal of some carbonate changes the volume ofliquid relative to the volume of carbon dioxide and, assuming a constanttemperature, there is a loss or reduction of carbonation pressure.

According to the present invention the carbonation of the liquidremaining in the container is maintained under a constant pressure bymanipulation of the pump 19 to force atmospheric air into the air bag 16causing it to expand and occupy a greater volume within the containerand exert the same pressure on the gas above the liquid as had beenexerted before some of the liquid was drawn off through tap 9.Therefore, an equilibrium at the desired level of carbonation ismaintained without adding contaminating air or expensive carbon dioxideto the carbonating chamber.

The air bag 16 is made of resilient material and so dimensioned as to becapable of occupying virtually all of the space within the carbonatingchamber 15 so that constant pressure can be maintained on the liquidremaining within the container until substantially all of the liquid hasbeen drawn off.

To applicant's knowledge it has not heretofore been possible to maintaina constant pressure on the liquid remaining within a container after aportion of it had been drawn off without the expense of introducingadditional carbon dioxide gas or contaminating the liquid or itsheadspace with atmospheric air and airborne bacteria. According to thepresent invention constant pressure is kept on the liquid in carbonatingchamber 15 by varying the carbonating chamber volume through the use ofatmospheric air pumped into the air bag 16 by the manually operable pump19.

There is thus provided an improved carbonator which will effectivelyachieve and maintain a fixed level of carbonation on liquid which isperiodically drawn off and which requires no more carbon dioxide thanthat necessary for adequate carbonation of a specified liquid volume.

Although specific terms have been employed in the drawings andspecification they are used in a descriptive sense only and not forpurposes of limitation.

What is claimed is:
 1. A self-contained and portable carbonatingapparatus comprising a fixed volume rigid container, a resilient bagwithin the container defining a variable volume carbonating chamberbetween the resilient bag and the rigid container, a pump communicatingwith the resilient bag, a relief valve establishing selectivecommunication between the carbonating chamber and the atmosphere,whereby air may be purged from the variable volume carbonating chamberby pumping air into the resilient bag and activating the relief valve.2. A self-contained and portable apparatus for carbonating liquidscomprising a container, a carbonating chamber within the container, airactuated means within the carbonating chamber for selectively varyingthe volume of the carbonating chamber to effect a uniform carbonatingpressure in the carbonating chamber and to admit and discharge liquidfrom the carbonating chamber, means for introducing carbon dioxide intothe carbonating chamber, means for venting carbon dioxide from thecarbonating chamber to the atmosphere, means for introducing liquid intothe carbonating chamber, and means for withdrawing carbonated liquidfrom the carbonating chamber.
 3. Apparatus according to claim 2 whereinsaid air actuated means is an air bag and wherein a pump meansselectively introduces atmospheric air into the air bag.
 4. An apparatusaccording to claim 3 wherein said pump is mounted in one wall of thecontainer and is connected to an open end of the air bag and whereinsaid pump is manually operable.
 5. A structure according to claim 3wherein a check valve is positioned in one wall of the container toprevent flow of air from the air bag into the pump.
 6. Apparatusaccording to claim 2 wherein said means for introducing carbon dioxideinto the carbonating chamber comprises a carbon dioxide cartridge andmeans on one wall of the container for supporting said cartridge whileits contents are discharged into the carbonating chamber.
 7. A structureaccording to claim 6 wherein a check valve is incorporated in one wallof the container to prevent passage of carbon dioxide from thecarbonating chamber into the carbon dioxide cartridge.
 8. A structureaccording to claim 2 wherein said means for venting carbon dioxide fromthe carbonating chamber comprises a pressure relief valve communicatingwith the carbonating chamber and with the atmosphere.
 9. A structureaccording to claim 8 wherein said pressure relief valve is adjustable tovent carbon dioxide at different amounts of pressure.
 10. A structureaccording to claim 3 wherein means are provided for venting air from theair bag, said means comprising a pressure relief valve communicatingwith the air bag and with the atmosphere.
 11. A structure according toclaim 10 wherein said pressure relief valve is adjustable to vent air atdifferent pressures.
 12. A structure according to claim 11 wherein saidmeans for venting carbon dioxide from the carbonating chamber to theatmosphere comprises a pressure relief valve communicating with thecarbonating chamber and the atmosphere, the pressure relief valve forthe carbonating chamber and the pressure relief valve for the air bagbeing adjustable to vent at different pressures, and the pressure reliefvalve for the carbonating chamber adjusted to vent at a higher pressurethan the pressure relief valve for the air bag.
 13. Apparatus accordingto claim 2 wherein said means for withdrawing carbonated liquid from thecarbonating chamber comprises a spout on the container and valve meansselectively establishing communication between the carbonating chamberand the atmosphere through said spout.
 14. Carbonating apparatusincluding means to regulate the quantity of liquid to be carbonated,said means comprising a rigid container, a resilient, flexible,impervious bag within the container, means to vent air to the atmospherefrom the container exteriorly of the bag, means to pump air to expandthe bag to the limits of the container walls, a supply of liquid outsidethe carbonating apparatus, a tube submerged in said liquid supply andcommunicating with the container exteriorly of the bag, and means tovent air within the bag to the atmosphere allowing contraction of thebag to draw liquid from said supply through the tube and into thecontainer exteriorly of the bag.